Add bind_phone captcha scene across schema/runtime/UI, require captcha on
phone bind, return real captcha status objects instead of legacy option
aliases, and harden form discovery for page-sign auth forms.
Stop auto-running AKSRT_Settings_Migration, drop multi-option settings
merge and Zibll favicon aliases, remove the migration tools entry from
menus/schema, flatten admin sections so pages are not demoted into a
compat bag, and retire the migration-status payload for leftover SPA
routes after a full admin rebuild.